FORTRAN became so popular in the 1960's that other vendors started to produce their own versions and this led to a growing divergence of dialects (by 1963 there were 40 different compilers). The rapid growth brought FORTRAN 66 to be the first language to be officially standardized. Unfortunately, the standard did not give a clear, precise definition of FORTRAN. Therefore, in the 70's a new standard was published. The new standard became known as ANSI X3.9-1978, which was published by the American National Standards Institute. This standard was then adopted by the International Standards Organization (ISO) as an International Standard.  The language is commonly known as FORTRAN 77.  However, FORTRAN 77 had a number of old-fashioned facilities that might be termed deficiencies.   

Due to FORTRAN's inability to represent data structures sufficiently and the lack of dynamic storage, it became clear that a new language needed to be developed. These insufficiencies led to the development of FORTRAN 8x. The work took 12 years because the developers wanted to keep the efficiency of FORTRAN 77. Other languages came about; however, none could match the efficiency of FORTRAN. The standards preceding FORTRAN 90 attempted mainly to standardize existing extensions and practices. The reason for this was that there are many programs written in FORTRAN 77 and FORTRAN 66 which although old are still very reliable. Therefore, each addition allowed older versions still to be implemented. The approach to FORTRAN 90 was to allow programs to be more modernized.  Meaning, the new version would allow FORTRAN to become portable, efficient, safe and maintainable code.

In the last couple of years the FORTRAN 90 based language known as High Performance Fortran (HPF) has been developed. This language contains the whole of FORTRAN 90 and also includes other desirable extensions. FORTRAN 95 will include many of the new features from HPF.

In summary, FORTRAN was developed for the following: